--- gdl-0.9rc2-20090224/src/envt.hpp.friend	2008-06-10 14:43:43.000000000 -0600
+++ gdl-0.9rc2-20090224/src/envt.hpp	2009-02-25 11:38:48.000000000 -0700
@@ -162,6 +162,8 @@
     if( ix >= env.size()) return false;
     return ( env.Env( ix) != NULL);
   }
+
+  friend class DInterpreter;
 };
 
 // for UD subroutines (written in GDL) ********************************